The invention relates to duckboards.
A duckboard is a length of board laid, in use, on a surface--such as the ground--over which men, materials and/or equipment have to walk, be dragged and/or wheeled.
The purpose of conventional duckboards is to make the passage of the men, materials and/or equipment easier and/or safer than it would be without the use of the board. For example, the ground-engaging wooden duckboard gives a man a firm-footed passage over boggy ground, and reduces the dangers of him slipping or sinking if the board were not present. And as a similar example, the conventional roof crawling board spreads a man's weight over a greater area than that of the roof struts which, without the board present, could not withstand the pressure of his weight on their own relatively small area.
These conventional duckboards are widely used. But their use is largely confined to the building industry. They are essentially rigid structures, and they are also relatively heavy. They tend to be quite large. For all these reasons, they are not easily portable, nor can they be stacked or transported in relatively confined spaces.
The commercial building industry accepts that its equipment will, in general, be heavier, more bulky, and less easily carried, than the equipment which the amateur "do it yourself" builder or gardener seeks to use. Building has always been essentially a heavy labouring job. The rigidity, weight, and size of conventional duckboards has therefore not received any inventive attention. Whether they are used outdoors, (as in the two examples given above) or indoors (in a gymnasium for example), duckboards have always been relatively rigid, large, and heavy; and there has been no reason to think of altering these basic qualities.
The commerical builder may accept readily enough that duckboards are one of the items of equipment in which he must invest, and which he must be prepared to carry around with him from site to site. The amateur builder or gardener, without the muscle power or the storage space available to the professional, does not view them in the same light. There are many instances when he could use the advantages of a duckboard or a line of duckboards laid end-to-end. For example, when barrowing earth across his lawn to and from his garden compost heap. He may to so far as to use planks, laid end-to-end, if he has these available to protect his lawn. He is more likely, either not to have them available, or to be unwilling to wrestle with them every time he needs to run a heavy barrow over his turf.
There is, in the example just given, a clear need for some form of duckboard which the amateur would be willing to buy and to use. But it is equally clearly a need to which conventional duckboards provide no solution. They are too heavy, too big, and too rigid to be used by the amateur. But the professional who does use them sees no good reason why he should seek to alter them for his purposes.
In a situation where an amateur builder or gardener requires the use of a duckboard, if it is to be of use to him it will have to be light enough for him to be able to readily lift and transport manually the whole assembly himself.
An embodiment of the duckboard of the invention may be used in situations where a temporary roadway may be required over a poor surface such as for use in tranporting emergency relief in third world countries. In such cases, the duckboard can usefully be heavier than that used by a gardener but still needs to be light enough to be easily lifted by a few men and easily transported by a lorry also carrying other goods. In the following specification the term "relatively portable" will be taken to mean light enough to be portable and useful for its required intended purpose.